Melbourne's observation wheel.

Melbourne's observation wheel.

Crowds are gathering to gape at the Melbourne Star Observation Wheel, even though some onlookers are "too scared" to ride.

One of the wheel's cabins was taken out of commission Tuesday while Victoria's workplace safety authority investigates complaints of pods tilting and windows cracking.

The inquiry was prompted by several complaints from passengers who have ridden the wheel since it reopened on December 23.

WorkSafe confirmed an investigation was under way after concerns were raised by a passenger.

Despite the latest setback for the troubled tourist attraction, Miomi clothing boutique owner Riani Tran said that the recent safety concerns have had no impact on her business.

“Some customers have expressed that they are too scared to go on the wheel but it hasn't really changed anything because people are still visiting Docklands to go shopping,” she said.

Lotus Therapy Massage worker Will Guo is thrilled that the Observation Wheel is finally operating.

“Business has picked up and I've definitely had more customers walk through the door,” he said.

Botika Clothing employee Mikayla Payne said business had improved.

“Since the wheel opened it has been so much busier. Working on a weekday now feels like working during the mad rush that you experience on a weekend, she said”

At noon on Tuesday, there were long queues to get on the wheel, and other queues in the area to buy food and coffee.

The new 120-metre-tall Melbourne Star Observation Wheel replaced the first wheel, which was shut down in January 2009 when a three-day heatwave caused the brace and supports to buckle and crack only a month after it opened.

Operators said an "early warning" alarm was triggered twice since the wheel reopened but did not say what triggered the alarm or whether the incidents were connected.

Docklands Chamber of Commerce president Joh Maxwell encouraged Melburnians to embrace the wheel, which she believed was a new landmark for the city.

She said the latest setback for the tourist attraction was a minor teething issue.

"It's no different to you buying a new car. At some stage you may have a glitch or something ... let the people who are the experts at it sort it," she said.

With AAP